--- a/caps/src/nsScriptSecurityManager.cpp
+++ b/caps/src/nsScriptSecurityManager.cpp
@@ -1279,16 +1279,17 @@ nsScriptSecurityManager::CheckLoadURIWit
     // fail, because they may need a security check that we don't
     // provide.
     NS_ENSURE_FALSE(aFlags & ~(nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT |
                                nsIScriptSecurityManager::ALLOW_CHROME |
                                nsIScriptSecurityManager::DISALLOW_SCRIPT |
                                nsIScriptSecurityManager::DISALLOW_INHERIT_PRINCIPAL),
                     NS_ERROR_UNEXPECTED);
     NS_ENSURE_ARG_POINTER(aPrincipal);
+    NS_ENSURE_ARG_POINTER(aTargetURI);
 
     if (aPrincipal == mSystemPrincipal) {
         // Allow access
         return NS_OK;
     }
     
     nsCOMPtr<nsIURI> sourceURI;
     aPrincipal->GetURI(getter_AddRefs(sourceURI));